Интегральные усилители — Yamaha A-S3200

The Yamaha A-S3200 is the top model of Yamaha's A-S line of stereo integrated amplifiers, above the A-S2200 and A-S1200. Its circuitry is balanced along the whole path from the inputs to the speaker terminals, and it offers two XLR line inputs, a discrete phono section for MM and MC cartridges plus large illuminated level meters behind a diagonally cut glass window.

Key specs that matter

Rated power is 100 W per channel into 8 ohms and 150 W per channel into 4 ohms from 20 Hz to 20 kHz at 0.07% THD. For Europe Yamaha quotes a maximum of 170 W per channel into 4 ohms at 1 kHz and 0.7% THD, and dynamic power per channel is 120, 150, 200 and 300 W into 8, 6, 4 and 2 ohms. The response stays within 3 dB from 5 Hz to 100 kHz and within 0.3 dB over 20 Hz to 20 kHz. Damping factor is 250 or more at 1 kHz into 8 ohms. Noise figures are 110 dB for the CD-level inputs and 114 dB for both balanced inputs, and THD from those inputs to the speaker terminals is 0.035% at 50 W into 8 ohms. The chassis is 435 x 180 x 464 mm and weighs 24.7 kg.

Engineering and use context

The phono amplifier is built from a discretely configured MC head amplifier and a separate equaliser amplifier. MC sensitivity is 150 microvolts at 50 ohms and MM sensitivity 3.5 mV at 47 kilohms, with RIAA deviation within 0.5 dB, phono noise figures of 90 dB for MC and 96 dB for MM, and distortion to the line output of 0.02% for MC and 0.005% for MM. A 623 VA toroidal transformer feeds four 22,000 microfarad block capacitors, whose terminals are gilded oxygen-free copper held by brass screws. Internal speaker wiring is 2.7 mm PC-Triple C, and PP film capacitors are used in the signal circuits. The transformer, capacitors and heatsink bolt straight to the chassis, a Rigid Streamlined Construction adds further vibration control, and the heavy feet take either spikes or a scratch-resistant base, a design first made for the M-5000 and C-5000 separates.

Pairing

Both balanced inputs are rated at 200 mV into 100 kilohms, line inputs at 200 mV into 47 kilohms, and a main input at 1 V into 47 kilohms allows a separate preamp to drive the output stage. The feet use brass with a silver finish, and the front switches and knobs are machined for a precise tactile action. The brass speaker terminals are machined from solid stock and tighten by hand.

Alternatives

A step below sits the Yamaha A-S2200 integrated amplifier, rated at 90 W per channel into 8 ohms and fed by a 625 VA toroidal transformer.